Accession Number : AD0827770

Title :   THE USE OF STAR TRACKERS TO DETERMINE THE ATTITUDE OF AN ORBITING VEHICLE,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA EL SEGUNDO TECHNICAL OPERATIONS

Personal Author(s) : Brogan, W. L.

Report Date : NOV 1967

Pagination or Media Count : 69

Abstract : The use of star trackers to determine the attitude of an orbiting vehicle is investigated. The operational procedure is divided into three basic modes, the nominal star acquisition mode, the search mode, and the attitude determination mode. These modes and their various options are discussed in this report. Complete details are given for a deterministic solution and possible sequential filtering solutions are briefly mentioned. Details for these more complicated solutions are left for future studies. The computational aspects of the problem are summarized in terms of the required inputs and outputs and of the mathematical operations to be performed within the computer. Error analyses are provided for most of the operational modes. General equations for the resultant attitude errors are given, as well as specific examples. The error sources considered are ephemeris errors, attitude control system errors, star tracker instrument and mounting errors, and gyro drift mounting errors. Computational errors are not considered. (Author)

Descriptors :   *SATELLITE TRACKING SYSTEMS), (*STAR TRACKERS, GYROSCOPES, ATTITUDE CONTROL SYSTEMS, ORBITS, DATA PROCESSING, FLOW CHARTING, MATHEMATICAL ANALYSIS, ACCURACY.

Subject Categories : Space Navigation and Guidance
      Spacecraft Trajectories and Reentry

Distribution Statement : APPROVED FOR PUBLIC RELEASE